v3.21.2
U.S. and Europe Retrospective Responsibility Plans - Additional Information (Details)
€ in Millions, $ in Millions
 1 Months Ended 12 Months Ended
Sep. 30, 2020
USD ($)
shares
Sep. 30, 2021
USD ($)
Sep. 30, 2021
EUR (€)
Sep. 30, 2020
USD ($)
shares
Sep. 30, 2019
USD ($)
Jun. 21, 2016
EUR (€)
Class of Stock [Line Items]            
Omnibus loss sharing agreement percentage   66.6667% 66.6667%      
Litigation loss sharing agreement, obligation threshold | €           € 1,000
Limit of protection from VE territory covered losses           70.00%
Conversion adjustment denominator (in shares) | shares 100          
VE covered loss, maximum amount of loss to allow adjustment of conversion rate during six-month period | €     € 20      
Recovery through conversion rate adjustment   $ 2   $ (5)    
Series A convertible participating preferred stock            
Class of Stock [Line Items]            
Preferred stock issued $ 7,300          
Preferred stock, shares issued (in shares) | shares 374,819          
Cash paid for fractional shares of series A preferred stock $ 5          
Preferred Stock            
Class of Stock [Line Items]            
Recovery through conversion rate adjustment   $ 55   $ 164 $ 8  
Preferred Stock | Series A convertible participating preferred stock            
Class of Stock [Line Items]            
Preferred stock, shares issued (in shares) | shares [1]       0    
MasterCard            
Class of Stock [Line Items]            
Omnibus loss sharing agreement percentage   33.3333% 33.3333%      
[1] Increase, decrease or balance is less than one million shares.